Room temperature ethanol sensing by green synthesized silver nanoparticle decorated SWCNT

In this research, we report a new ethanol sensor based on green synthesis of silver nanoparticles (AgNPs) and their decoration on single wall carbon nanotubes (SWCNT) using reduction process. A single wall carbon nanotube was treated by chemical process using H2SO4/HNO3(3/2). AgNPs prepared directly with mixing sol-gel nano-component with treated carbon nanotube using ultrasonic/sol gel method. The AgNP/SWCNT was characterized by Field emission scanning electron microscopy (FESEM), thermo gravimetric analysis (TGA) and high-resolution transmission electron microscopy (HR-TEM). The sizes of the silver nanoparticles decorated on SWC NTs ranged from 10 to 15 nm. The AgNP/SWCNT nano composite was used as a sensing layer between the Gold electrodes in the vertically gold- insulator (SiO2)-gold structure (100 nm 500 nm(-1) 100 nm(-1)). The sensor measured using a semiautomatic gas setup. The AgNP/SWCNT reflects a reasonable sensing for ethanol gas in the ambient temperature. The results revealed that the AgNP/SWCNT sensor has a Response value in the order of 7.1-45.3 at room temperature for 1-200 ppm (8-116 s response time and 7-38 s recovery time) respectively with a limit of detection (LOD) of 2 ppb with a full recovery response.